Process



April 4, 1944. R. H. GARDNER PROCESS -Filed Feb. 7, 1941 agitated' asf.'4,1'c44 PROCESS Robert H. Gardner, Munster, Ind., assigner. to

Sinclair Refining Company, New York, N. Y., a corporation of MaineApplausi-im* retmm 7, 1941, semi No. :mais z claims. v(ci. 26o-csa Thisinvention relates improvements in the production oi motor fuel bythealkylation of Aoleilns, particularly butylenes, by isobutane by reactionin the presence of strong sulfuric acid.

Processes for the pr uction of motor fuel by such alkyiation operationsare known, and in general involve the reaction of butylenes withisobutane in the presence of strong sulfuric vacid at temperaturesranging from around 40 to 70 F., with the use of a large excess ofisobutane in the reactionlrnixture, with agitation effective to permitintimate contact of the various components, etc. By such operations, itis possible to produce products available for aviation gasoline havingan octane number (CFR motor method) ranging upwards of 90. l l

In .the reaction mixture, at least two competing reactions ,take place,the alkylation referred to and reaction ofthe oleilns alone, whichapparently involves initial polymerization followed by decomposition togive saturated bodies and bodies having a greater degree of unsaturationthan Ithe olefins or polymers. To the extent that this olefin reactiontakes place, the quality of the product obtained is reduced, or theyield is reduced, because any saturated products of proper boiling rangefor aviation fuel so produced lower the octane value of the finalproduct, while any saturated products ci improper boiling point reducethe yield and the unsaturated 4bodies apparently form stable complexeswith'the acid and increase acid consumption.

There are three isomeric butylenes (disregarding geometrical isomers),that is, isobutylene, butylene-l and butylene-2. f these, butylene-2 hasa boiling point very close to that of butane, while the boiling point ofbutylene-1 and isobutylene, and also isobutane, are lower. Also of thebutylenes, butylene-2 is the least reactive, while isobutylene is themost reactive, both in reactions invovlng only olefins, the alkylationreaction and other reactions.

From the standpoint of alkylate quality, measured in termsgof value asan aviation gasoline, the

. alkylate produced from butylene-Z is not of as high quality as thatproduced from isobutylene. However, as a practical matter, the lesser.reactivity of butylene-Zis reflected in its tendency to form AoleilnIreaction products.' so that under many conditions ofy operation,butylene-2 will give, on alkylation with isobutane. a better product.than will isobutylene or butylene-l, because of alesser production ofsuch undesirable products. This vbetter quality produced with butylene-2isa result of thedegree'of admixture with products produced from olefinsalone rather than to an inherent quality of the alkylate itself. In-

herentiy, thi,l alkyiate from isobutylene is superior, but because,other conditions being the same, it usually contains a larger proportionof undesirable products, the alkylate ordinarily produced is of lowerquality than that produced from tion usually higher, because of theincreased formation of products which form stable complexes with theacid.

In accordance 4with the present invention, a motor .fuel of high octanevalue, for example, 95 orhigher, is produced'irom the gases of a crackedstock, together with any extraneous isobutane which may be available, byselectively supplying to the alkylation reaction zone the isobutyleneand isobutane while minimizing theamount of butylene-2 supplied theretoand carrying out the alkylation reaction under conditions which arefavorable for the production of alkylate, and in particular, at a lowtemperature, for example, 40 to 60 F., high ratio of isobutane to olefinand with intimate contact of the acid and the i hydrocarbon phasesprovided by effective agitation. Under such conditions, alkylate havingan octane number as high as 95 (CFR motor method) or higher may beproduced in excellent yields, with low acid consumption ranging around0.9 lb. per gallon or even lower. Thel important factors in carrying outthe invention are the minimizing of the butylene-2 in the olefin feedand the carrying out of the reaction under conditions favorable toalkylation and which mini? mise' the olefin interreactions whichordinarily radically reduce the quality of the product wheremajorproportions of isobutylene are included in the olefin feed andincrease the acid consumption. y

The invention will be illustrated in connec=v tion with the appendedflow sheet, which shows diagrammatically an integrated alkylation andpolymerization plant adapted for the carrying out of the process ofproducing an olefin polymer useful as a motor fuel as well as a highquality alkylate from the gases of a cracked stock.

A cracked stock. is debutanized in the de butanizer l2, the bottomsgoing to storage and the overhead, having the following composition:

' Y Per cent Ethylene 0.5 Ethane Propylene Propane i 20.9 Isobutane i6.3 lsobutylene 10.5 Butylene-l v y 7.0 N-butane 30.5 Butylene-Z 11.0

being passed through the hydrogen sulfide relbutylene-l or butylene-Z,and the acid consumpbutanizerli, having the composition:

Mmmm-11m un'emue me; u u

The rcsultingmdrocarbon mixture, zimbarrelsperdanisproportionedattlpoint2t, 'lsfban'els line?. tothe deisnbutaniser Il and 1685 barrels'through' linetothevaporlnerandheaterlllandthence tothepolymeiimtiontower I2. '1'heproductsotl the polymerization operationare condensed-in.

the condenser I8, pass to. the surge'tankll and then-'to the debutaninerIl. The bottomslrom the delmtanizer, 388 barrels per day, containingthe' polymer, are drawn of! to 'me'overhead fraction, 1210 barrels perriait,4 having the comis passed through the lines Il and '41, aftercaustic washing in the caustic washer l5 to the deisobutanzer 48.' Alsoted to this delscbutanizer are 206 barrels perday of isobutane stockfromoutsldesources having the composition:

Per cent "Propane 85.? Isolmtane '28.6 n-butane '35.7

and 82o barrels per day eroverheen from the ae- TheY overhead from thedeisobutanizer I9, 2020 barrels per day, having the composition:

y 4Percent Ethylene 0.6 m ,me 6.1 lllrcirylene 4.0 Propane 129.0Isohutnne 45.5 Isobutylme 5.0 Butylene-il 3.9 N-butane 5.8' Bntyiene-20.1

ismssedbymnmsz mazsmtmaepmpanizer'il. Thebottansfrcmthedeisohutanizer,1005 barrels per das, composition:

Per cent N-nutane am Bulene-Z 18.3

vis dischargedtostmngmand maybensedorzfuelorgnsnline-hlendingtocomrolrmeryvapor pressure..

Theoverhesdfromthedemopanimrll, equivn lent mlz'bnnels'per Percent Ethme15.1

Pmpylene 10.0

Propme 72.5 A I I. I

redisear-nahme.

depropanine'r nrlmbarelsper d8yhaving the composition:

Per cent Isolmtne "15.2 Isohutylene 8.3 Buiwlene-l 6.5 "1r-battue.A f Y.9.8' Butylemsa Y 0.2

.is passed to the alkylaition'reaction zone'through the heat exchanger cl, in wnie'h it is bregntmto heat exchange relationship with .thehydrocarbon Y- from the alkylation reaction, the Vwater settler 62butanizer 4I. The overhead from this debutanizer, i

andthe chillen,

Thev reaction l stratiiied in the settlers 3l and 33, the hydrocarbonpassmg through the heat exchanger 6.0, then being caustic `washed an'dcharged tg the dethecompomtion of which is given above, ispassed Vto thedeisobutanizer 49', while the bottoms Iractiox'r, equivalent to316barrels per day., an1d'con-y sistin'g of hydrocarbons heavier than thelive car# bon atom hydrocarbons, ischarged to the -rc-run position:

Per cent Ethylene 1 0.6 Ethane V6.9 Propylene 1.2 Propane 28.8'-Isobutane 8.7 Isobutylene 1.4 Butylene-l 2.0 N-butalne 42.1 Butylene-Zy8.3

column from which 300'barrels Der day of allwlate having an octanenumber of 95.6'are obtained., 'f

The. alkylation reactor used Ain lthe 'operation described consisted oi'a. verticalcylindricai ves.

sel with a conical bottom provided with anfinner annular sleeveextending from near the bottom to nearthe topandwith .a pum'p in thevbottom which caused rapid circulation of the reaction mixture from 'thebottom upwardbetween the sleeve and the wall-of the vessel and downwithin Per cent Isobutane 85.7 N-biltane 14.3

and derivedaswmbe Y the sleeve. VThe followlngtable VGives datapertinent to this operation.

0st course, other tapes of reactors, such as time tanks, provided withmeans for external recirmilaticn ami cooling, tubular reactors, etc.,may be used. Y

I claim: d 1. The mocess of producing high octane motor fuel from thefourcarbon atom hydrocarbon gases of a cracked stock` which comprises(1) debutanizing a cracked stock, (2) dividing the cverhead from thedemtanizing'into two fractions of similar compositim each comprisingisobutane,

' .isobutylene Imi Miene-2, (3) subjecting one zonen-rennen. 1-1Theprocessasinthe'predingclaimdnfractionto a polymerization operationto polymerlaetheoleiinitlihm, debutanizing the productor thepolymerization, (5) passing thectherfxaciionnndtheoverheadfrmnthedehutanizingotthelolymertoadeisobutanizerandsubjectingtheuverheadtherefrnhanalkylawhichthe conditions of alkrlationare favorable to thealkylatimreaclimandumfavorabletoside mEQAB-UNER.

from the alkylation is

